I have a 2015 Honda Accord exl and the check charging system light came on. I checked for voltage at the battery and it was not charging. When I connect the positive lead wire of my meter to the alternator and negative lead to the negative terminal of the battery I get no voltage but when I put the negative lead on the positive of the battery I get 11.6 volts. The battery alone has 12.7 volts. I checked my other car and I got the same battery voltage when I connect the red lead to alternator and black lead to negative. Changed alternators and got the same results. How can two positives give me voltage.

 

Found the problem. The wire to the alternator goes around the back of the engine to the left side of the fuse block. The terminal must have gotten hot and melted the plastic preventing a connection. Alternator is working now.